The instrument requested is a Leica TCS LSI zoom confocal microscope system. We are requesting the current configuration because it has the greatest flexibility in capability and can capture images from live tissues and cells as well as image very large fields of view. The other confocal systems currently available on campus are not sufficient for the projects described because they 1) are too slow, 2) cannot image large fields of view without stitching, 3) are highly scheduled already, 4) are not the correct configuration for our user needs being primarily inverted micrscopes with small working distances and 5) do not have an environmental chamber for imaging large live specimens. There is not currently available on this campus any truly comparable confocal microscope in terms of capability. Hence this microscope will enable studies that were not previously possible or were only achievable in a substandard way with a tremendous investment of both money and time. The Leica TCS LSI differs significantly from other confocals primarily in the ability to image large fields of view and to zoom from low to high magnification. The software is easy to use and the image capture is high resolution and very fast;a major advantage for a multi-user piece of equipment requiring high throughput. The new equipment is needed to advance the research programs of 14 investigators on the UC Davis campus. The users represent a broad range of scientific interest and span four schools/colleges on campus (Medicine, Veterinary Medicine, Agriculture and Environmental Sciences and Engineering). The research is highly focused on both basic sciences and human health and includes studies of inhalation toxicology of air pollutants, animal models of asthma, studies of the circulatory system including heart/vascular disease, brain and nervous system dysfunction, stem cell repopulation of airways and whole animal studies of medaka fish. All the proposals have one common element, the need for a microscope with a large field of view and high resolution to analyze complex composites of cells either in culture or in tissues, quickly. Placement of this equipment in core facilities at UC Davis will also facilitate the projects of graduate students, postdoctoral fellows, residents and professional school (DVM or MD) researchers. Outreach to other campus users will be facilitated by maintaining the equipment in a core facility, listing the equipment on the core and center websites and by inclusion in Dr. Van Winkle's teaching in campus courses on imaging. The overall benefits to the UC Davis campus are many. This equipment fits well with the research needs of the UC Davis community, which has included a recent emphasis on the childhood health disorders autism and asthma that require large field imaging capability for neurons and airways respectively.